Railway-brake



UNITED STATES PATENT Grumm- WILLIAM P. THOMPSON, OF PHILADELPHIA,PENNSYLVANIA,

RAILWAY- BRAKE.

SPEGIFIC'ATTON forming part of Letters Patent No. 239,887, dated April5, 1-881.

Applicationfile'd November 6,1880. (No model.)

Toall whom it may concern i Be it known that I, WILLIAM P. THOMPSON, ofthe'city and county of Philadelphia, State of Pennsylvania, haveinvented certain new and useful I mprovenents in Brakes for Retardingand Arresting the Motion of Railway- Garria'ges; and- [do hereby declarethe following to bee sufficiently full, clear, and exact descriptionthereof toenable'others skilled in theart to make and use thesaidinvention.

My invention relatest'o that class of railwaybrakes which operate by thepressure of air, steam, or other fluid, having a reservoir on theengiiie connected by a pipe with auxiliary res ervoirs under eacli'car,which auxiliary reser voir'sare connected by pipes to cylindersandpistons or diaphragms operating the brakerods. These pipes or channelsbetween; the auxiliary reservoirs and brake-cylinders have differentialvalves placed therein fordirecting and controlling the flow of the fluidto and from the brake-cylinders, and are known to railway men asautomatic brakes? in coutradistinction to pneumatic or other fluidbrakes which areoperated by the direct flow of air fromthe tank ontheengine to the brakeoperating cylinders, which latter arrangement ispopularly termed by railroad men the old Westinghouse system of brakes.The operatin g of the automatic brakes isunder the control of theengineer on the locomotive, who, by letting the pressure on oroff thepipe ex-' over the speed of the train by enabling him to make moreimmediate and eli ective use of the pressure in the large reservoir onthe locomotive than has been practicable with the appliances heretoforeknown, and thus to enable the engineer, at his option, to operate thebrakes as old Westinghouse or other equivalent brake acting by pressuredirectly transmitted from the engine-reservoir, or to operate the brakeas new automatic by the press urc of the fluid in the auxiliaryreservoirs under the cars, so that, in the event of the pressure in thevessels under the several cars proving inadequate to work the brake asautomatic and check the speed of the train, they can by this duplexsystem hepr'oinptly operated by direct application of fluid pressuretransmitted through the pipes extending from the reservoir and pump onthe engine.

The/nature of my invention may be briefly stated to consist of a duplexor. double system of valves and pipes extending through the train,connected to the usual reservoir and piston or diaphragm cylinders,through one of which set of pipes the reservoirs under the cars mayreceive a chargeof compressed air or other fluid, and, by means of thedifferential valves'kn'own as automatic pl'aced'therein, the brakesmaybeoperated on the automatic system, and through the other set ofpipes the air or other fluid pressure may be let on to the brake pistoncylinder through a differential valve which opens and closes as thepressure is let on or off through this second line of pipe, or is let onto both the auxiliary and, through the automatic valve, to thebrake-piston cylinder simultaneously throughout the train. y

My invention consists, further, in the construction of an impr'ovedformof duplex valve orcock, by means of which the engineer in the engine maymore conveniently and instantly, without risk of mistake, apply hisbrake as newantomatic, or. as Westinghouse, or direct old way. In thisduplex cook or valve the lever is soarranged that to put off the braketheengineer pushes the lever'ahead in the direction of the motion of thetrain. To put on the brake automatic the lever is pulled back, or, inthe reverse way of the motion of the train, half-way and to put on thebrake harder,

or by the duplex pipes, it is pulled farther back,

or continued in its motion to a greater distance. This duplex cook orvalve has a pointer or index extending out to a marked rod or dial-platewhich will in the light visibly indicate the effect of the position ofthe lever, and in the dark will, by falling into depressions, indicatewhich openings are in communication. This marked bar is reversible, andon its other side has another set of marks and cavities or recesses foruse when the duplex system has become inoperative, or when, through anyother reason, it is desirable to cease using the second line of pipe andthe automatic valves of the first line and operate the brakes throughthe first line of pipes as a direct-actin g air, steam, or fluid brakemechanism. When the brake apparatus is in use in this way the effect ofbringing the opening into communication by turning the barrel of theduplex cock has adifferent result. It is then necessary that the dialshould read differently for the same position of the cock-lcver.

The mode of making and using this invention is herein fully explained,and shown in the drawings annexed, in whieh Figure 1 is a plan of myinvention as applied underneath a car with the pressure from thereservoir under the engine to the small reservoir and the brakes oft"the wheels. Fig. 2 is a plan of the same, showing the pressure exhaustedfrom the first line of pipe and the pressure from the small reservoirputting on the brakes. Fig. 3 is a plan of the same, showing thepressure from the second line of pipes for putting on the brakes. Fig. 4is a plan of lever, pointer, and indicator, with marks for the duplexbrake ready for use. Fig. 5 is a plan of same, showing the dial orindicator bar reversed for the direct brake, ready for use. Fig. 6 is anelevation of this indicator-bar. Fig. 7 is a side elevation of duplexcock, showing bearing on which the dial-bar may be revolved. Fig. 8 is aplan, where the pipe P instead of communicating directly with thecylinder 0, is attached to the pipe P between the reservoir R and theautomatic valve V, which arrangement charges the reservoir It, as wellas the piston-cylinder 0, through the pipe P The same letters ofreference apply to the same parts in the several figures.

A is the pipe leading from the tank or reservoir on the locomotive,whichis kept continuously supplied with air or other fluid pressure.

0 is the cylinder which contains the piston or diaphragm connected tothe brake-rods, and is connected by the pipes P, P and P to the cylinderand the first line of pressure-pipe, P. To these pipes is attached theautomatic valve V, from which extends the pipe P through the doublecheck-valve Qjto the second line of pipe,

suitable pointer or indicator; G, a marker upon I a pivot-support; and II are spring-catches or end supports for the indicator-bar, which is bythem kept firmly in its place until they are made to release it forreversing.

When the pressure from the engine-tank operates the brakes directly theautomatic valve performs no other function than the exhausting of thebrake cylinders in releasing the brakes.

Having described my invention, what I claim is 1. In a system of air orother elastic fluid pressure brakes, a duplex system of pipes andvalves, whereby the engineer may, at his option, from the engine, applydirect pressure from the engine-tank, or the reaction of compressedfluid in tanks on the cars, such change of mode of operation beingeffected by valves operated bycurrents of fluid directed and controlledby the engineer, all arranged substantially as and for the purpose setforth.

2. An additional line of pipe extending from the engine through thetrain for the purpose of directly supplying fluid under pressure fromthe engine to the brake-cylinders, in combination with saidbrake-cylinders, susceptible alternatively of operation by re-expansionof air or other elastic fluid contained in reservoirs on each car, allarranged as shown and for the purpose described.

3. In fluid-pressure brakes, the combination of valves shown anddescribed for intercepting and changing the direction of fluid from theen gine-tank to the auxiliary tanks and con- WM. P. THOMPSON.

In presence of- 'GEORGE Rnx MAGEE, J. DANIEL EBY.

